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Abstract:

The system includes a first heat exchanger in which the refrigerant is
injected directly into the content of the first liquid circuit through at
least one nozzle to simultaneously capture latent heat from the content
as purified frozen liquid pieces are formed. It also includes a second
heat exchanger in which the refrigerant transfers the latent heat
captured from the content of the first liquid circuit to a content of the
second liquid circuit, thereby raising the content of the second liquid
circuit in temperature. The proposed concept provides designers with
opportunities to create highly efficient systems and methods where the
latent heat extracted for the purification is immediately employed to a
useful purpose.

Claims:

1. A system for transferring latent heat from a first liquid circuit to a
second liquid circuit and for simultaneously separating a content of the
first liquid circuit into a purified product and a by-product, the
by-product containing concentrated impurities that were separated from
the purified product, the system including: a network of conduits
containing a refrigerant that is substantially immiscible and unreactive
with the content of the first liquid circuit; a first heat exchanger in
which the refrigerant is injected directly into the content of the first
liquid circuit through at least one nozzle to create frozen liquid pieces
containing the purified product and to simultaneously capture the latent
heat released upon freezing these liquid pieces; a second heat exchanger
in which the refrigerant transfers the latent heat captured from the
first liquid circuit to the second liquid circuit, thereby rising a
content of the second liquid circuit in temperature; and a refrigerant
compressor in fluid communication with the network of conduits, the
compressor being located downstream of the first heat exchanger and
upstream of the second heat exchanger.

2. The system as defined in claim 1, wherein the first heat exchanger
includes: a first inlet through which the content of the first liquid
circuit is supplied to the first heat exchanger; a second inlet through
which the refrigerant coming from the second heat exchanger is supplied
to the at least one nozzle; a first outlet from which the frozen liquid
pieces are retrieved out of the first heat exchanger; a second outlet
from which the refrigerant is directed to the refrigerant compressor; and
a third outlet for retrieving the by-product out of the first heat
exchanger.

3. The system as defined in claim 2, wherein the first heat exchanger
includes a thermally-insulated pressure vessel, the pressure vessel
including: a first portion including a main liquid-containing chamber and
a plenum chamber, the second outlet of the first heat exchanger being
located in the plenum chamber; and a second portion including a water
column having a bottom end opened into the main chamber of the first
portion through a passageway located beneath a normal water level
separating the main chamber and the plenum chamber, the water column
having an upper end where is located the first outlet of the first heat
exchanger.

4. The system as defined in claim 3, wherein the first heat exchanger
includes a substantially vertically-extending pipe having an upper
discharge end opening into the first portion of the pressure vessel, the
at least one nozzle discharging the refrigerant into the pipe.

5. The system as defined in claim 4, wherein the upper discharge end is
located in the plenum chamber or on a bottom of the main chamber right
under the plenum chamber.

6. The system as defined in claim 4, wherein the pipe includes a bottom
inlet receiving a flow of the content of the first liquid circuit from
elsewhere in the system, the at least one nozzle being configured and
disposed to inject the refrigerant substantially perpendicularly with
reference to the flow coming out of the bottom inlet.

7. The system as defined in claim 6, wherein the bottom inlet is
connected to the water column through a conduit.

8. The system as defined in claim 7, wherein the water column includes a
plenum chamber preventing the frozen liquid pieces from plugging the
conduit between the water column and the bottom inlet.

9. The system as defined in claim 4, wherein the system further includes
an icicle cutter device located in the pipe, the icicle cutter device
being adjacent to the at least one nozzle.

10. The system as defined in claim 3, wherein the system further includes
means for moving the frozen liquid pieces from the main chamber into the
water column.

11. The system as defined in claim 10, wherein the means for moving the
frozen liquid pieces include an auger mechanically connected to a motor.

12. The system as defined in claim 3, wherein the second inlet includes a
float valve regulating a flow of refrigerant supplied to the at least one
nozzle in response to a variation of an actual water level in the main
chamber with reference to the normal water level.

13. The system as defined in claim 3, wherein the pressure vessel
includes a device for evacuating the frozen liquid pieces, the device
being located at the upper end of the water column immediately upstream
of the first outlet of the first heat exchanger.

14. The system as defined in claim 1, wherein at least some of the
content of the second liquid circuit is preheated using waste heat from a
motor driving the refrigerant compressor.

15. The system as defined in claim 1, wherein the system further includes
a gas removing device located upstream of the first heat exchanger, the
gas removing device removing dissolved gas from the content of the first
liquid circuit.

16. The system as defined in claim 1, wherein the system further includes
an ice crusher located downstream of the first outlet of the first heat
exchanger and receiving the frozen liquid pieces therefrom.

17. A system for transferring latent heat from a first liquid circuit to
a second liquid circuit and for simultaneously separating a content of
the first liquid circuit into a purified product and a concentrated
by-product, the system including: a heat pump unit including: an
evaporator section where a refrigerant is vaporized at a first pressure
directly into the content of the first liquid circuit and where some of
the content of the first liquid circuit transfers enough of its latent
heat to the vaporized refrigerant to form floating purified frozen liquid
pieces, the refrigerant being substantially immiscible and unreactive
with the content of the first liquid circuit; a compressor section where
the refrigerant at the first pressure is compressed up to a second
pressure; and a condenser section where the refrigerant coming from the
compressor is put in heat exchange relationship with a content of the
second liquid circuit and where the latent heat carried by the
refrigerant is transferred to a content of the second liquid circuit
before the refrigerant goes back to the evaporator section in a liquefied
form; and a pressure vessel enclosing the evaporator section of the heat
pump unit.

18. The system as defined in claim 17, wherein the pressure vessel
includes: a first portion in which are located a main liquid-containing
chamber and a plenum chamber that is located above the main chamber, the
main chamber including: an upper end in direct fluid communication with a
bottom end of the plenum chamber; and an upper interior wall configured
and disposed to form a downwardly slanted path for the frozen liquid
pieces; the first portion of the pressure vessel having a normal liquid
level defining a boundary between the upper end of the main chamber and
the bottom end of the plenum chamber; a second portion in which is
located a water column having an upper end and a bottom end, the bottom
end of the water column being in fluid communication with the main
chamber using a passageway that is located through the upper interior
wall beneath the normal liquid level and downstream of the downwardly
slanted path; and a by-product outlet provided at a substantially
downmost location within the main chamber.

19. The system as defined in claim 18, wherein the pressure vessel
includes an auger that is positioned inside the main chamber, the frozen
liquid pieces being conveyed along the downwardly slanted path into the
passageway upon rotating the auger.

20. The system as defined in claim 17, wherein the first pressure is
higher than the atmospheric pressure outside the pressure vessel.

21. A method for purifying a first liquid content and simultaneously
heating a second liquid content using latent heat from the first liquid
content on a continuous basis, the method including: retrieving enough of
the latent heat from the first liquid content to transform a first part
of the first liquid content into purified frozen liquid pieces using a
vaporized refrigerant injected directly into the first liquid content,
the refrigerant being substantially immiscible and unreactive with the
first liquid circuit content; separating substantially all of the
refrigerant from the first liquid content in which it was injected;
separating the purified frozen liquid pieces from a second part of the
first liquid content having a concentrated amount of contaminants;
raising the second liquid content in temperature using the latent heat
retrieved from the first liquid content and carried by the refrigerant;
and supplying additional amounts of the first liquid content to maintain
a substantially constant level of the first liquid content.

Description:

CROSS-REFERENCE

[0001] The present case claims the benefit of U.K. patent application No.
0921315.8 filed 5 Dec. 2009, which is hereby incorporated by reference in
its entirety.

TECHNICAL FIELD

[0002] The technical field relates generally to open geothermal heat pump
systems.

BACKGROUND

[0003] Minimizing energy consumption is highly desirable whenever the
costs of energy can have a direct impact on the overall operating costs
of a system. Very often, minimizing energy consumption also reduces
carbon footprint.

[0004] There are different possible approaches for minimizing energy
consumption. One approach is to use more efficient machines and method
for extracting energy from an available heat source. Heat pumps systems
are one example of machines following this approach when applied to
heating. In these systems, heat from a first medium is captured using a
refrigerant circulating in a cold side and a second medium is heated
using the same refrigerant circulating in a hot side. Heat pump systems
are also well known for use in refrigerators or air conditioning systems.

[0005] Still, heat pump systems can be used for freezing a liquid, for
instance water, in order to purify it. When water freezes, it forms
substantially pure ice crystals. Over the years, this characteristic was
used for different purposes, such as the recovery of fresh water from
salt water or for treating effluents from industrial processes. Examples
of systems are disclosed in U.S. Pat. No. 3,098,735 issued on 23 Jul.
1963 to Clark, U.S. Pat. No. 3,137,554 issued 16 Jun. 1964 to Gilliland
et al., U.S. Pat. No. 3,338,065 issued 29 Aug. 1967 to Ashley, and U.S.
Pat. No. 4,199,961 issued on 29 Apr. 1980 to Carter et al., to name just
a few.

[0006] Some heat pump systems were designed for extracting latent heat
released when liquid water freezes in their cold side. When freezing,
liquid water goes through a phase change and releases about 335 KJ of
latent heat per kilogram of water. This represents about 15 times more
energy than using only sensible heat from cold liquid water. As an added
benefit, less water is required. However, one of the challenges of
ice-generating heat pump systems is the relative complexity involved in
operating them on a continuous basis. In particular, ice tends to
accumulate on the cold side of the heat pump systems, thereby requiring
frequent defrost cycles. This reduces the overall efficiency of these
systems.

[0007] U.S. Pat. No. 4,671,077 issued on 9 Jun. 1987 to Paradis discloses
a system where the latent heat from freezing water is used as a source of
energy. The water can be salt water or polluted water and this water can
be purified as a result of the freezing. Although the disclosed system
has potential benefits in terms of energy efficiency, there are still
many challenges that one would need to overcome before such system can be
operated continuously with an optimum efficiency and on a large scale.

[0008] Accordingly, there is still room for many improvements in this area
of technology.

SUMMARY

[0009] In one aspect, there is provided a system for transferring latent
heat from a first liquid circuit to a second liquid circuit and for
simultaneously separating a content of the first liquid circuit into a
purified product and a by-product, the by-product containing concentrated
impurities that were separated from the purified product, the system
including: a network of conduits containing a refrigerant that is
substantially immiscible and unreactive with the content of the first
liquid circuit; a first heat exchanger in which the refrigerant is
injected directly into the content of the first liquid circuit through at
least one nozzle to create frozen liquid pieces containing the purified
product and to simultaneously capture the latent heat released upon
freezing these liquid pieces; a second heat exchanger in which the
refrigerant transfers the latent heat captured from the first liquid
circuit to the second liquid circuit, thereby rising a content of the
second liquid circuit in temperature; and a refrigerant compressor in
fluid communication with the network of conduits, the compressor being
located downstream of the first heat exchanger and upstream of the second
heat exchanger.

[0010] In another aspect, there is provided a system for transferring
latent heat from a first liquid circuit to a second liquid circuit and
for simultaneously separating a content of the first liquid circuit into
a purified product and a concentrated by-product, the system including: a
heat pump unit including: an evaporator section where a refrigerant is
vaporized at a first pressure directly into the content of the first
liquid circuit and where some of the content of the first liquid circuit
transfers enough of its latent heat to the vaporized refrigerant to form
floating purified frozen liquid pieces, the refrigerant being
substantially immiscible and unreactive with the content of the first
liquid circuit; a compressor section where the refrigerant at the first
pressure is compressed up to a second pressure; and a condenser section
where the refrigerant coming from the compressor is put in heat exchange
relationship with a content of the second liquid circuit and where the
latent heat carried by the refrigerant is transferred to a content of the
second liquid circuit before the refrigerant goes back to the evaporator
section in a liquefied form; and a pressure vessel enclosing the
evaporator section of the heat pump unit.

[0011] In another aspect, there is provided a method for purifying a first
liquid content and simultaneously heating a second liquid content using
latent heat from the first liquid content on a continuous basis, the
method including: retrieving enough of the latent heat from the first
liquid content to transform a first part of the first liquid content into
purified frozen liquid pieces using a vaporized refrigerant injected
directly into the first liquid content, the refrigerant being
substantially immiscible and unreactive with the first liquid circuit
content; separating substantially all of the refrigerant from the first
liquid content in which it was injected; separating the purified frozen
liquid pieces from a second part of the first liquid content having a
concentrated amount of contaminants; raising the second liquid content in
temperature using the latent heat retrieved from the first liquid content
and carried by the refrigerant; and supplying additional amounts of the
first liquid content to maintain a substantially constant level of the
first liquid content.

[0012] Further details on these aspects as well as other aspects of the
proposed concept will be apparent from the following detailed description
and the appended figures.

BRIEF DESCRIPTION OF THE FIGURES

[0013] FIG. 1 is a semi-schematic view illustrating an example of a system
implementing the proposed concept;

[0014] FIG. 2 is a semi-schematic view illustrating an example of the
interior of the Rankine cycle device shown in FIG. 1; and

[0015] FIG. 3 is a semi-schematic view illustrating an example of the
interior of the pressure vessel in the system shown in FIG. 1.

DETAILED DESCRIPTION

[0016] FIG. 1 is a semi-schematic view illustrating an example of a system
10 implementing the proposed concept. The system 10 is used for
transferring latent heat from the content of a first liquid circuit 12 to
the content of a second liquid circuit 14 in order to simultaneously
purify the first liquid content and heat the second liquid content with
the latent heat from the purification of the first liquid content.

[0017] A first part of the first liquid content is purified when it forms
frozen liquid pieces as a result of a phase change. The first liquid
content is then divided into a purified product and a by-product, which
by-product contains concentrated impurities mixed with a second part of
the first liquid content. The system 10 is able to run on continuous
basis and in a very efficient manner.

[0018] The first liquid content can be water. This water can originate
from a natural or artificial body of water, for instance an underground
source, a river, a lake, a pond or the sea to name just a few.

[0019] The system 10 can thus take advantage of the geothermal energy
present from a body of water. It is also possible to use water from a
storage tank or water coming directly out of another system. Still, the
first liquid content can be an effluent from an industrial process, for
instance one used in the papermaking industry, the food industry or the
petroleum industry.

[0020] In the illustrated example, water in the first liquid circuit 12
comes from a pond 20 in which the water contains fines and other chemical
products that were produced when separating oil from tar sands. Using
this water as a source of energy in the system 10 will provide an
opportunity for purifying this water from at least some of the
contaminants therein. The water is supplied through an inlet conduit 22
of the first liquid circuit 12 using a pump 24. This water passes through
a vacuum water tank system 26 or another kind of gas removing device
capable of removing dissolved gas from the content of the first liquid
circuit 12. The vacuum water tank system 26 removes substantially all of
the dissolved air in the water to prevent air from contaminating a
refrigerant used in the system 10.

[0021] As shown in FIG. 1, the first liquid circuit 12 is connected to a
thermally-insulated pressure vessel 30 enclosing a first heat exchanger
of the system 10. Further details on the pressure vessel 30 are given
later in the description.

[0022] The second liquid circuit 14 of the illustrated example also
contains water. When passing through the system 10, the water of the
second liquid circuit 14 is heated and becomes hot water for use in an
industrial process, such as a tar sand extraction process or the like.
The hot water does not go back to the second liquid circuit 14
afterwards. Other configurations and arrangements are also possible. For
instance, when the hot water is used for heating a building or the like,
the second liquid circuit 14 can form a closed loop. Many other variants
are possible as well.

[0023] It should be noted at this point that although water is the only
liquid used in the illustrated example, other liquids or mixtures of
liquids could be used as well.

[0024] The system 10 includes a network of conduits containing a
refrigerant. The network of conduits is part of a heat pump unit
integrated into the system 10. The heat pump unit includes an evaporator
section located in the pressure vessel 30. The evaporator section is
where the liquefied refrigerant is injected at a first pressure directly
into the water from the first liquid circuit 12 and where some of this
water transfers enough latent heat to vaporize the liquid refrigerant
into gas bubbles so as to form frozen purified liquid pieces. In the
evaporator section, both the water and the refrigerant are subjected to a
phase change. Bringing the two in close direct contact at the moment they
go through their phase change creates a very efficient heat transfer. The
refrigerant is subsequently separated from the unfrozen water and the
frozen liquid pieces. The refrigerant will be recycled back into the
network of conduits.

[0025] The refrigerant used in the heat pump unit is substantially
immiscible and unreactive with the content of the first liquid circuit
12. For instance, when the liquid in the first liquid circuit 12 is
water, the refrigerant can be a hydrocarbon refrigerant such as butane,
isobutane, propane, etc. The hydrocarbon refrigerant can also be a
mixture of two or more hydrocarbons in order to obtain a specific
evaporating pressure. Other refrigerants can be used as well.

[0026] The heat pump unit further includes a compressor section where the
refrigerant coming from the evaporator section at the first pressure is
compressed up to a second pressure. It also includes a condenser section
where the refrigerant coming from the compressor section is put in heat
exchange relationship with the water of the second liquid circuit 14. The
refrigerant then becomes a liquid as a result of another phase change.
This second phase change of the refrigerant releases an important
quantity of latent heat that is transferred to the content of the second
liquid circuit 14. The refrigerant goes back towards the evaporator
section afterwards. The condenser section defines the second heat
exchanger of the system 10. The second heat exchanger is schematically
depicted at 32.

[0027] In the illustrated example, the compressor section includes two
distinct compressors 40, 42 mounted in parallel, each driven by a
different motor arrangement. Using only one compressor or even more than
two compressors mounted in parallel or in series is also possible. Both
compressors receive the gaseous refrigerant from the evaporator section
in the pressure vessel 30. The first and/or the second compressor 40, 42
can be driven by a corresponding electric motor or another available
source of mechanical power.

[0028] In the illustrated example, the first compressor 40 is driven by an
internal combustion engine or a gas turbine engine. The engine is
schematically depicted in FIG. 1 at 44.

[0029] The second compressor 42 of the illustrated example is driven by a
Rankine cycle device 200. FIG. 2 is a semi-schematic view illustrating an
example of the interior of the Rankine cycle device 200 shown in FIG. 1.
This Rankine cycle device 200 includes a steam turbine 202 connected to
an independent closed loop fluid circuit 204 in which flows a fluid, for
example water, transformed into steam upstream of the steam turbine 202.
For better efficiency at lower temperatures, other fluids can also be
used, for instance hydrocarbons, halocarbons, etc. The fluid circuit 204
circulates the fluid into a boiler 206 receiving heat from the hot
exhaust gases of the engine 44 circulating through a chimney 45. The
boiler 206 transforms the fluid into the steam for use in the steam
turbine 202. The fluid at the outlet of the steam turbine 202 is sent to
a condenser 208 that cools the fluid using fresh water supplied through a
fresh water inlet conduit 47. The condenser 208 warms the fresh water,
which then exits the condenser through a conduit 49 as warm fresh water.

[0030] The illustrated example also includes another independent closed
loop fluid circuit 48 coming from the engine 44. This circuit 48 is
connected to the cooling jacket of the engine 44. It thus captures waste
heat from the engine 44. It is connected to another heat exchanger 210 in
the Rankine cycle device 200 to preheat the fluid in the fluid circuit
204 coming from the condenser 208. A pump 212 is provided to circulate
the fluid in the fluid circuit 204.

[0031] As shown in FIG. 1, the system 10 also includes a heat exchanger 50
receiving the warm fresh water from the conduit 49. In the heat exchanger
50, some of the remaining sensible and latent heat in the combustion
gases from the engine 44 are transferred to the warm fresh water, thereby
increasing its temperature even more and increasing the overall energy
efficiency of the system 10.

[0032] When leaving the heat exchanger 50 through a conduit 51, the warm
fresh water is sent towards the second heat exchanger 32 and is mixed
along the way with additional fresh water coming from another heat
exchanger 52 through a conduit 53. The additional fresh water is
preheated using a waste energy source flowing in a conduit 55. The
conduit 56 is connected to the inlet of the second heat exchanger 32 and
the content therein forms the content of the second liquid circuit 14 in
the system 10. The conduit 57 is connected to the outlet of the second
heat exchanger 32 and sends the hot water where it is needed.

[0033] In the illustrated example, the refrigerant leaving the compressor
section passes into an air/oil separator 58 before entering into the
second heat exchanger 32. Also, the refrigerant leaving the second heat
exchanger 32 in the conduit 59 is sent to an accumulator 60, from which
the refrigerant will be directed to the pressure vessel 30 using a
conduit 62 to repeat the cycle.

[0034] The thermally-insulated pressure vessel 30 mainly includes two
portions. The first portion of the pressure vessel 30 is where frozen
liquid pieces are created by the direct injection of the refrigerant. It
is thus at the first pressure. Although the first pressure maintained
inside the first portion of the pressure vessel 30 is generally much
lower than the second pressure at the output of the compressors, the
first pressure can sometimes be significantly higher than the atmospheric
pressure. It can also be lower than the atmospheric pressure in some
designs. One challenge is thus to retrieve the frozen liquid pieces out
of the pressure vessel 30 through an outlet while still maintaining the
first pressure therein. A solution found to this challenge was to provide
the pressure vessel 30 with an elongated and thermally-insulated water
column 70 and to collect the frozen liquid pieces at an outlet located at
an upper end 72 of the obliquely-disposed water column 70. The water
column 70 constitutes the second portion of the pressure vessel 30.

[0035] In the illustrated example, the first pressure is higher than the
atmospheric pressure outside the pressure vessel 30. The water column 70
is designed be high enough so as to compensate for the pressure
differential between the first pressure and the atmospheric pressure. The
weight of the water thus counterbalances the pressure differential and
the upper end 72 of the water column 70 can thus remain exposed to the
atmospheric pressure.

[0036] The frozen liquid pieces float at the surface of the unfrozen water
inside the pressure vessel 30. Once they are inside the water column 70,
they rise by themselves towards its upper end 72. From there, they are
directed to an ice crusher 80 using a device for evacuating the frozen
liquid pieces. This device can be for instance an auger 82, as shown. The
auger 82 can be rigid or flexible, depending for instance whether the
interior of the water column 70 is straight or curved. The auger 82 is
powered by a motor 84 in the illustrated example. Other kinds of device
for evacuating the frozen liquid pieces can be used as well.

[0037] The frozen liquid pieces retrieved out of the water column 70 are
sent into a chute 86 directing them into the ice crusher 80. The ice
crusher 80 can reduce the frozen liquid pieces into a snow-like material,
for instance using blades revolving at high speeds. The snow-like
material then falls below the ice crusher 80 and eventually forms wet
snow stacks 88, as shown in FIG. 1. Crushing the frozen liquid pieces
increase the overall contact surface of the purified product with the
surrounding air and/or rain water, thereby making it easier to melt the
product into liquid water that is substantially purer than the water in
the inlet conduit 22 of the first liquid circuit 12. An air blower 89 can
be provided to push the falling snow-like material where needed, for
instance at the bottom of a hill adjacent to a lake 87 or another body of
water.

[0038] The water column 70 is also useful for decanting the contaminants
in the unfrozen water. In use, most contaminants will to fall by gravity
towards the bottom of the pressure vessel 30. However, a relatively wide
water column 70 will give the opportunity to contaminants carried away by
the flow of frozen liquid pieces to find their way to the bottom. Still,
the water column 70 is also useful for precooling the unfrozen water just
before transforming some of it into the frozen liquid pieces. As the
frozen liquid pieces rise, the water in the water column 70 will become
increasingly cooler due to an exchange of sensible heat. This liquid
water will be used for making the next frozen liquid pieces. The water is
sent back to the first portion of the pressure vessel 30 through a
conduit 74. A plenum 76 is provided on the side of the water column 70 to
separate the unfrozen water from the frozen liquid pieces. This prevents
frozen liquid pieces from plugging the conduit 74. It should be noted
that although the plenum 76 is located near the upper end 72 in the
illustrated example, it is possible to retrieve the water from somewhere
below along the water column 70.

[0039] If desired, the water flowing in the conduit 74 can be used for
other purposes, for instance for cooling a building or an industrial
process.

[0040] It should be noted that the height of the water column 70 can be
reduced by using various possible alternative arrangements. For instance,
one can use an arrangement involving spaced-apart traps (not shown)
provided along the water column 70 to retrieve the frozen liquid pieces.

[0041] The first pressure inside the first portion is maintained by
opening only one trap at a time. Other arrangements are possible as well.
Furthermore, if the first pressure is lower than the atmospheric
pressure, the height of the water column 70 would be significantly
reduced compared to what is shown in FIG. 1 since the upper end 72 would
be located near or even below the normal water level 104.

[0042] FIG. 3 is a semi-schematic view illustrating an example of the
interior of the pressure vessel 30 in the system 10 shown in FIG. 1.
However, only the bottom end of the water column 70 is visible in FIG. 3.

[0043] As can be seen in FIG. 3, the first portion of the pressure vessel
30 encloses a main liquid-containing chamber 100 and a plenum chamber 102
that is located above the main chamber 100.

[0044] The main chamber 100 has an upper end in direct fluid communication
with a bottom end of the plenum chamber 102. The main chamber 100 is
filled with the water from the first liquid circuit 12 up to a normal
liquid level 104. The normal liquid level 104 defines the boundary
between the upper end of the main chamber 100 and the bottom end of the
plenum chamber 102.

[0045] In the illustrated example, the frozen liquid pieces are formed in
an ice maker 110 that is part of the first portion of the pressure vessel
30. The ice maker 110 has an upper discharge end 112 into the plenum
chamber 102. This ice maker 110 includes an elongated
vertically-extending pipe 114 filled with water coming from the conduit
74.

[0046] In use, the refrigerant is maintained under conditions of
temperature and pressure which permit the refrigerant to expand, vaporize
and move upwardly through the water while a multitude of small frozen
liquid pieces are created. Thus, as the liquid refrigerant is injected
directly into the water through one or more nozzles 116 and is subjected
to a sudden drop in pressure, its temperature falls below the freezing
temperature of water. However, since the refrigerant has a boiling
temperature that is well below 0° C., the refrigerant vaporizes
and is subjected to a phase change. This creates the refrigerant bubbles
in the water and the capture of latent heat turns some of the water into
the frozen liquid pieces. Furthermore, the refrigerant bubbles push the
mixture of unfrozen water, frozen liquid pieces and refrigerant up.

[0047] The nozzle or nozzles 116 are oriented substantially
perpendicularly with reference to the incoming flow of water. This water
flows upwardly from an inlet located at the bottom end of the pipe 114 of
the ice maker 110. New frozen liquid pieces are formed as the liquid
water, the vaporized refrigerant and other newly-formed frozen liquid
pieces rise into the pipe 114. Once they reach the upper discharge end
112, they pour out into an upper part of the plenum chamber 102. An
icicle cutter device 118 can be provided at the bottom of the pipe 114 to
prevent ice from building on or around the nozzle or nozzles 116.

[0048] If desired, the upper discharge end 112 of the pipe 114 can be
located on the bottom of the main chamber 100 right under the plenum
chamber 100.

[0049] It should be noted at this point that regardless of the fact that
the water supplied in the ice maker 110 can be near its freezing
temperature, a substantial amount of latent heat can still be captured
from it. The reason is that this latent heat will come from the phase
change of the water.

[0050] Before going through the nozzle or nozzles 116, the liquefied
refrigerant from the conduit 62 passes into a water/refrigerant separator
120 in which liquid water is separated from the liquefied refrigerant.
The presence of water with the refrigerant is due to the fact that small
amounts of water are carried by the gaseous refrigerant when it leaves
the plenum chamber 102 through a refrigerant outlet of the pressure
vessel 30. This water could potentially freeze and plug the refrigerant
circuit immediately upstream of the nozzle or nozzles 116 if it is not
removed. The condensed water is sent back inside the pressure vessel 30
using a dedicated conduit 122. A float valve 124 prevents the liquefied
refrigerant from entering the conduit 122 if not enough water is present
to prevent it. The refrigerant leaving the separator 120 is channeled
into a conduit 126.

[0051] In the illustrated example, a float valve 130 located adjacent to
the normal water level 104 regulates the flow of refrigerant to the ice
maker 110 using a float 131. This way, if the water level is too low, the
flow of refrigerant can be interrupted so as to prevent the refrigerant
from going into the main chamber 100 and possibly reaching the water
column 70. A screen 129 is provided to prevent frozen liquid pieces from
accumulating around the float 131 and make it defective.

[0052] As can be seen in FIG. 3, the upper discharge end of the pipe 114
can be located above the normal water level 104 of the main chamber 100.
The unfrozen water and the frozen liquid pieces coming out of the ice
maker 110 are directed to the main chamber 100 using an inclined surface
106 of the plenum chamber 102. This gives time for any refrigerant still
trapped in the unfrozen water and/or adhering to the frozen liquid pieces
to be separated from them. The unfrozen water and the frozen liquid
pieces eventually fall into the main chamber 100 and the frozen liquid
pieces will initially float at the normal water level 104.

[0053] The refrigerant coming inside the plenum chamber 102 is retrieved
out of the pressure vessel 30 from a refrigerant outlet 133 that is in
fluid communication with a conduit 132 channeling the refrigerant towards
the compressor section. A screen separator 134 can be provided on the
inside to prevent unfrozen water and frozen liquid pieces from plugging
the refrigerant outlet 133.

[0054] As can also be seen in FIG. 3, the main chamber 100 includes an
upper interior wall 140 that is configured and disposed to form a
downwardly slanted path for the frozen liquid pieces. Still, the bottom
end of the water column 70 is made in fluid communication with the upper
interior wall 140 of the main chamber 100 using a passageway 142 that is
located downstream of the downwardly slanted path for the frozen liquid
pieces. Since the passageway 142 is beneath the normal liquid level 104
when the main chamber 100 is filled with water, there will be no direct
path for the gaseous refrigerant between the plenum chamber 102 and the
passageway 142.

[0055] In use, the frozen liquid pieces are conveyed along the downwardly
slanted path into the passageway 142 using a mechanized arrangement. In
the illustrated example, this arrangement includes an auger 150 driven by
a motor 152. Rotating the auger 150 can push the frozen liquid pieces
along the downwardly slanted path and then into the passageway 142, from
which they will float towards the upper end 72 of the water column 70.
The auger 150 also acts as a pump to push the unfrozen water towards the
water column 70, from which it will be recycled through the conduit 74
that feeds the ice maker 110 by gravity. Other arrangements can be used
as well, for instance a conveyor, a rope with a disk assembly, etc. It is
also possible to use a pump mounted along the conduit 74.

[0056] Water in the main chamber 100 becomes increasingly concentrated
with impurities as the purified frozen liquid pieces enter the water
column 70 and their impurities are left behind. The impurities tend to
accumulate at the bottom of the main chamber 100 by gravity. These
impurities and the water at the bottom form the concentrated by-product.
The pressure vessel 30 includes an outlet 160 provided at a substantially
downmost location 162 within the bottom end of the main chamber 100 to
retrieved the by-product out of the pressure vessel 30. The flow of the
by-product through the outlet 160 is regulated by a valve 164.

[0057] The supply of water coming from the first liquid circuit 12 can be
controlled using, for instance, a float sensor or the like at the upper
end 72 of the water column 70. This way, the flow of the first liquid
circuit 12 can be regulated to maintain the system 10 balanced. In the
illustrated example, as shown in FIG. 1, an actuated valve 170 is
provided on the first liquid circuit 12 and the water is supplied
directly through an inlet of the main chamber 100. The actuated valve 170
can be connected to the float sensor using a wired connection. The wired
connected is schematically depicted in FIG. 1 at 172.

[0058] As can be appreciated, the present concept provides a method for
purifying a first liquid content and for simultaneously heating a second
liquid content using latent heat from the first liquid content on a
continuous basis. In this method, enough of the latent heat from the
first liquid content is retrieved to transform a first part of the first
liquid content into purified frozen liquid pieces using a vaporized
refrigerant injected directly into the first liquid content, the
refrigerant being substantially immiscible and unreactive with the first
liquid circuit content. Substantially all of the refrigerant is separated
from the first liquid content in which it was injected. The purified
frozen liquid pieces are separated from a second part of the first liquid
content containing a concentrated amount of contaminants. The second
liquid content rises in temperature using the latent heat retrieved from
the first liquid content and carried by the refrigerant. Additional
amounts of the first liquid content are supplied to maintain a
substantially constant level of the first liquid content.

[0059] If desired, the content of the first liquid circuit 12 can be
pre-filtered, for instance using filters, centrifugal machines,
mechanical vapor compression systems and/or reverse osmosis systems.

[0060] Overall, the proposed concept provides designers with opportunities
to create highly efficient systems and methods where the latent heat
extracted from the purification is immediately employed to a useful
purpose. The systems and methods are also capable of being run on a
continuous basis.

[0061] The present detailed description and the appended figures are meant
to be exemplary only. A skilled person will recognize that variants can
be made in light of a review of the present disclosure without departing
from the proposed concept.

Patent applications in class Fractionally solidifying a constituent and separating the same

Patent applications in all subclasses Fractionally solidifying a constituent and separating the same